Hook rule



C. P. ASHEL.

April 30, 1940.

HOOK RULE Filed June 1, 1939 lllllll IIN) INVENTOR Uh sier P she ATTORNEYS.

Patented Apr. 30, 1940 y e UNITE'DSTATES f Y Y 2,199,235

g PATENT loiFlcr.

` HOOK RULE j l Chester Paul Ashel, Appleton, Wis., vassignorto The L. S. Starrett Company, Athol, Mass., `a, u corporation of Massachusetts applicati@ June rissa's'eriaiNdpzvssi -7 claims. (difesi-473)' is a new accessory of varied utility and usable with straight edges ofl measuring or othery tools or with parts, such as the blades of` adjustable squares and like tools.

The illustrative form shown in the accom,- panying drawing is a practical attachment well adapted for convenient use and'for commercial production,` which issug'gestive of other modications of form and use which will readily occur to those skilled in this trade. i u

In the drawing, in which parts are identified by usual conventional reference characters,

Fig. 1 illustrates a clamping attachment in accordance with my invention, applied as a `hook rule to the blade of an adjustable square.

Fig. 2 is a sectional view of the block of such attachment with a fragment of a longitudinally grooved blade lodged in its channel and with hook pinv in place but with clamp screw removed.'

Fig. 3 is a View also in section of the. block in reversed position showing both the .hook` pin and clamp screw but without any blade.

Fig. 4 is a transverse sectional view longitudinally through the block with pin hook and clamp screw removed.

Fig. 5 is a View transversely of the block vin partialsection and showing a clamp screw and `nut in place in relation to a blade taken on a general line indicated at 5-K-5, of Fig. l, and

Fig. 6 is a plan view of such a rule'block illustrated as on a blade but Viewed from its lower side. y

My novel hook rule attachment is adapted to be used with any straight edged blade but more particularly a blade channeled on one side face between its edges. As'in Fig. 1, I preferably provide it as a block I and this, in the form shown, is preferably an 4oblong block slightly longer than its depth and having one corner on its outer end beveled as at 2 substantially to the line of the pin bearing so as-to expose the pin at this cornerrof-.the block. Ihe block lI: .is lon]- :er1 Ledge I .of thev block.

gitudinally channeled as at 3 to receive a straight adapted to its Width, as indicated in Figs. 1, 2 and 5. y

Adjacent what maybe considered as itsfinner end; regarded with reference to the head H of the adjustable square indicated in Fig.y1,I form a clamp'scr'ew receiving aperture-4` which is circular at its upper end where it'passes through the upper part of the Vblock I above thegupper wall or edge contacting 'surface 5 of the channel.

3. This portionof-,the'fcla'mp aperture is transversely tapped as `at 6 ior receiving a retaining screw 'I (Fig. v5).

Below its upper end'the' clamp ,aperture las it intersects the blade receiving channel 3 preferably forms at one sidey a half cylindrical groove 8 in which can be lodged laghalf round stem of a threaded blade clamp 9 having itsface flattened off as at Iso as to bear against a blade such'a's B having a usual clamping groove bl between its opposite straight edges. 'the half round threaded vclamp piece 5 is formed Ywith a foot I I Vadapted. to fit within the groove b.

Above the half'roundp'ortion of the threaded clampv piece 9 itis `formed of the full diameter of the wire of the stock and threaded as at 9 to receive a nut I2 for tightening the foot II against the upper edge of the groove b (Fig. 5).

At what we may consider vas its outer end as viewed in Fig. 1, i. e. away from the head I-I of the 'square of which the bladeBjmay happen to be part asa tool commonly inv machinists boxes, I provide an aperture I3 to receive -the pin I4'which serves as-the hook. This aperturepasses transversely through the upper part of the block I on what is really'vitssolid back opposite kto its open channel 3 and continues as opposite grooves I3, I32 in the side walls of jthechannel 3.

Referring to Fig. 4 `itwill 'beY-not'edthat the 'channel 3 preferably divides the block Ilr unsym- Ametrically so that one wall is more deeply grooved as at I3 than the other atv |32.` The unsymmetrical channel 3 also makes unsymmetrical the 'formation of the semi-cylindrica1 groove 8 for the half round. screw portion 9-with a block of minimum thickness.

The hook pin I4 is preferably.acylindricali pin of uniform diameter throughout, but it vis* en'- gaged frictionally -progressively towards the low- Preferably,4 belowv the' f edge or blade of any form or type of construction At its lowergend upper portion I3 in whichithelpin-Id has an easy t for entry,-theoppositepin receiving grooves I3' taper. drillingy pir-like expedienttd'obtain the desired frictional t with a maximum at the lower edge I which comes adjacent the median line of the blade B when so mounted.

The hook pin I 4 is preferably larger in diameter than the thickness of the usual blade on which such an attachment is intended to be used. This gives a maximum clamping surface or end bearing for the blade even though the blade may be actually somewhat off the vertical axial center of the pin due to the difference in thickness of the walls of the block I as before explained.

The hook pin I4 is normally set out as indicated in Fig. 2 when the device is used as a hook rule. If it be desired to use the attachment with an adjustable square, as suggested in Fig. 1, the pin I4 may be pushed down to agreater extent as may be desired and the head or like member 4 of the square or other instrument having a face h may be moved so that a piece lof' work placed between the hook pin I4 and the face h may be roughly calipered.

Various other uses as well as modifications in form will be readily suggested to those skilled in the art by my illustrative embodiment of my invention as shown in the drawing and as discussed in my foregoing specication and as hereafter claimed.

What I therefore claim and desire to secure by Letters Patent is:

1. A hook rule attachment for the blade of an adjustable square or like device having an engageable clamping groove between its longitudinal edges, said attachment including a block channeled to provide a longitudinal blade bearing, said block having a verticalclamp receiving aperture through its top, the inner `face of said blade bearing channel being vertically grooved in axial alinement with said aperture, a threaded clamp screw in said aperture having a flattened portion extending into said vertical groove to provide a side bearing for said blade and having a foot at its lower end adapted to enter the groove in the blade, a nut on the screw for tightening the clamp foot in said blade groove, a pin receiving aperture in said block adjacent an outer end thereof and extending through the longitudinal blade bearing channel, and a cylindrical hook pin in said aperture of greater length than the vertical depth of said blade bearing, said pin being of greater diameter than the thickness of the blade and being adjustably clamped against the end of the blade as said blade is clamped in its bearing when said nut tightens the clamp foot Vin the blade groove.

2. A hook rule attachment for the blade of an adjustable square or like device having an engageable clamping groove between its longitudinal edges, said attachment including an oblong block having a longitudinal blade bearing and beveled on its outer end face at the channel line of its blade bearing, said block having a vertical clamp receiving aperture through its top, the inner face of said blade bearing being vertically .grooved in axial alinement with said aperture, a threaded clamp screw in said aperture having 'a attened portion extending into said vertical groove and having a foot at its lower end adapted to enter the blade groove, a nut on the screw for tightening the clamp foot in the groove of said blade, a hook pin receiving aperture in said block adjacent an outer end thereof and extending through the longitudinal blade bearing, and a cylindrical hook pin of greater length than twice the vertical depth of said blade frictionally adjustable in said aperture, said hook pin being of greater ydiameter than the thickness of the blade and being adjustably clamped against the end of the blade as said blade is clamped in its bearing when said nut tightens the clamp foot in said groove.

3. A hook rule attachment for the blade of an adjustable square or like device having an engageable clamping groove between its longitudinal edges, said attachment including a block channeled to provide a longitudinal blade bearing, said channel dividing the block into walls of unequal thickness, said block having a vertical clamp receiving aperture through its top over said channel,

' the inner face of the thicker wall being vertically grooved in axial alinement with said aperture, a threaded clamp screw in said aperture and having a flattened portion extending into said vertical groove and having a foot at its lower end adapted to enter the blade groove, a nut on the screw for tightening vthe clamp foot in the blade groove, a hook pin receiving aperture in said block adjacent an outer end thereof and extending through the longitudinal blade bearingy channel, and a cylindrical hook pin of greater than twice the vertical depth of bearing, said pin being of greater diameter than the thickness of the blade and being adjustably clamped against the end of the blade as said blade is clamped in its bearing when said nut tightens the clamp foot in said groove.

4. A hook rule attachment for the blade of an adjustable square or like device having an engageable clamping groove between its longitudinal edges, said attachment including a block channeled to provide a longitudinal blade bearing, said channel dividing the block into walls of unequal thickness, said block having Va vertical clamp receiving aperture through its top the inner face of said blade bearing being vertically grooved in axial alinement with said aperture, a threaded clamp screw in said aperture having a flattened portion extending into said vertical groove and having a clamp foot adapted to enter said blade groove, a nut on the screw for tightening the clamp foot in the blade groove, a hook pin receiving aperture in said block adjacent an outer end lthereof and extending through the longitudinal blade bearing channel and symmetrically of the plane of said block and forming unsymmetrical grooves at the opposite inner faces of the bearing channel walls, and acylindrical hook pin of greater than twice the vertical depth of bearing, said pin being adjustably clamped against the end of the blade as said blade is clamped in its bearing when said nut tightens the clamp foot in said groove. Y

5. A hook rule attachment ior the blade Vof an adjustable square or like device having an engageable clamping groove between its longitudinal edges, said attachment including a block channeled to provide a longitudinal blade bearing, said block having a vertical clamp receiving aperture through its top, the inner face of said blade bearing being vertically grooved in axial alinement with said aperture, a threaded clampI screw in said aperture having a flattened portion extending into said vertical groove and having a clamp foot adapted to enter said vblade groove, a nut on the screw for tightening the clamp foot in the blade groove, a hook :pin receiving aperture in said block adjacent an outer end thereof and extending through the longitudinal blade bearing channel, anda cylindrical hook pin of greater than twice the vertical depth of Vbearing and of a diameter greater than the Width of the ,blade bearing, said hook pin being of greater diameter than the thickness of the blade and being adjustably clamped against the end of the blade as said blade is clamped in its bearing when said nut tightens the clamp foot in said groove.

6. A hook rule attachment for the blade of an adjustable square or like device having an engageable clamping groove between its longitudinal edges, said attachment including "a block channeled to provide a longitudinal blade bearing, said blade bearing dividing the block into Walls of unequal thickness, said block having a vertical clampI receiving aperture through its top, the inner face of said blade bearing having a groove in the inner face of the thicker wall in axial alinement with said aperture, a threaded clamp screw in said aperture and having a flattened portion adjacent its lower end, a nut on the screw for tightening the clamp foot in the blade groove, a hook pin receiving aperture in said block adjacent an outer end thereof and extendingA through the longitudinal blade bearing channel and forming unsymmetrical grooves at the opposite inner faces of the bearing walls, and a cylindrical hook pin of greater than twice the vertical depth of bearing, said pin being adjustably clamped against the end of the blade as said blade is clamped in its bearing when said nut tightens the clamp foot in said groove.

7. A hook rule attachment for the blade of an adjustable square or like device having an engageable clamping groove between its longitudinal edges, said attachment including a block channeled to provide a longitudinal blade bearing, said blade bearing dividing the block intowalls of unequal thickness, said block having a vertical clamp receiving aperture through its top, the inner face of the thicker wall being grooved `in axial alinement with said aperture, a threaded clamp screw in said aperture having a flattened portion extending into said vertical groove and having a clamp foot adapted to enter said blade groove, a nut on the screw for tightening the clamp foot in the blade groove, a hook pin receiving aperture in said block adjacent an outer end and extending through the longitudinal blade f bearing and symmetrically of the plane of it and forming unsymmetrical grooves at the opposite inner faces of the bearing channel walls, and a lcylindrical hook pin of greater than twice the vertical depth of bearing,` and of a diameter greater than the width of the blade bearing, said.

groove.

CHESTER PAUL ASHEL. 

